Spring scale



May 5, 1931.

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3 Tr E 0 Ne N 8, Wm m 1 I T a s. G. AVERELL srnmc- SCALE Filed June 6, 1929 5 lvesi'erG 23; h

Patented May 5, 1931 UNITED STATES PATENT OFFICE SYLVE STER G. AVERIELL, OF NEW YORK, N. Y., ASSIGNOR TO JOHN CHATILLON 8c SONS, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK SPRING SCALE Application filed June 6, 1929.

This invention relates to spring scales, and has particular reference to a novel construc tion for correcting the reading of the indicator on the dial due to the expansion or contraction of the springmaterial and changes in the stiffness of the springs due to changes in temperature.

A primary object of the invention is to provide a simple, practical and reliable construction which will be accurately responsive to changes in temperature conditions to shift the position of the rack with reference to the pinion, the said rack having teeth pitched at such apredetermined constantly increasing angle from the bottom to the top that as the rack is shifted laterally, it actuates the pinion to correct the indicator errors due to changes in length and stiffness of the springs caused by temperature changes.

A further object of the invention is to provide a construction of the type referred to which may be conveniently embodied in a mechanism support of the type disclosed in my copen.ding application filed June (5th, 1929 Serial No. 368,856, (Case No. 5).

With the above and other objects in view which will more readily appear as the nature of the invention is better understood, the same consists in the novel construction, combination and arrangement of parts hereinafter more fully described, illustrated and claimed.

A preferred and practical embodiment of the invention is shown in the accompanying drawings, in which Figure 1 is an elevationsho wing part of the dial and the present improvements also in elevation. I

Fig. 2 is a vertical cross-sectional view taken on the line 22 of Figure 1.

Fig. 3.is a horizontal cross-sectional view taken on the line 33 of Figure 1.

Similar reference characters designate corresponding parts throughout the several figures of the drawings. 7

In the embodiment of the invention shown in the drawings, the scale mechanism is supported on a hanger designated generally as H, the said mechanism including the loading springs S suspended from the top of the Serial No. 368,857.

hanger and supporting the runner A. The dial shaft 1 is journaled as at 2 in the hanger H and carries the dial hand 3 at one end thereof, while the intermediate portion carries the pinion 4 having the hub 5 which prevents longitudinal shifting on the shaft 1.

The pinion 4 meshes with the rack R whose lower end is provided with a shaft 6 extending to opposite sides thereof and loosely mounted in the forked arms 7 of a carrier bar 8 mounted on the runner A. The carrier bar 8 is adapted to be shifted longitudinally of the runner by the adjusting screw 9 which engages the offset portion 10 of the carrier bar, to compress a spring 11 hearing against an offset abutment-12 of the runner through which the threaded shank of the screw 9 passes. By adjusting the screw 9 the relative vertical position of the carrier bar 8 may be adjusted to bring the rack into proper initial engagement with the pinion r.

In connection with the rack B it will be observed that the same is especially designed to cooperate with a thermostat device designated generally as T. I rack R is provided with teeth 13 which are cut on the bias, or, in other words, at a gradually increasing angle to the axis of the pinion 4. I The teeth at the point of contact with the pinion at no load are cut at such an angle to the axis of the pinion 4 that lateral movement of the rack across the pinion will correct the zero reading of the indicator for any predetermined range of temperature cl'iange preferably from 20 to F. which includes the variations in temperature to which scales are ordinarily subjected. Each succeeding tooth is cut at such a progressively increasing angle that it will actuate the pinion to correct the indicator reading for changes in stiffness of the springs due to temperature changes.

Referring to the thermostat T it will be observed that the same is mounted at its lowor end upon a suitable bracket 14 affixed to the carrier bar 8, while its upper end is bifurcated to fit into the reduced portion 15 of the shaft 6 carried by the end of the rack. While the connection between the thermostat and the shaft 6 may assume various forms,

That is to say, the

- struck out from the body of the hanger N,

while the upper end which bears against the rack is provided with an offset portion 21 guided in a suitable opening in one of the down turned sides of one of the intermediate portions of the hanger.

WVhen the scale is made it is designed to operate Within certain temperature ranges and the lateral position of the rack with reference to the pinion is initially predetermined so that as the thermostat T bends under changing temperature conditions the shaft 6 of the rack will be moved to the left or right in Figure 2 to bring the rack in position to present more or less of the angular pitch of its teeth into engagement with the pinion. Under high temperature conditions the thermostat 'I will move to the left and shift the rack in the same direction thus bringing the right side of the teeth 13 in position to'engage with the pinion 4. On the other hand, when the scale is subjected to lower temperature conditions the thermo stat T will move toward the right and cause a corresponding shift of the rack to bring the low side of the teeth in position to engage the pinion. This arrangement is due to i he fact that under higher temperature conditions a lesser movement of the indicating device is required for a given movement of the rack and at lower temperatures a greater movement of the indicating device is required for a given travel of the rack, and this is accomplishedby shifting the rack to the left as the temperature rises and to the right as the temperature falls.

From the foregoing it will be apparent that the novel and distinctive feature of the present invention resides in the provision of a thermostatically controlled and laterally shifta'ble rack having teeth out on a gradually increasing bias or angle with reference to the axis of the pinion to compensate or correct for the physical changes-in the spring due to changing teni iieratui'e conditions.

Without further description it is thought that the features and advantages of the'in vention will be readily apparent to those skilled in the art, and it will of course be understood that clianges in the form, proportion and minor details of construction may be resorted to, without departing from the spirit of the invention and scope of the appended claims.

1. In a sprin scale, the combination of an indicator, an indicator pinion and a rack having its teeth out at a progressively increasing angle, and a thermostat adapted to automatically change the position of the rack laterally with reference to the teeth of the pinion under changing temperature conditions so as to correct indicator errors due to temperature changes.

2. In a spring scale, the combination of an indicator, and indicator pinion mounted in a relatively fixed position, a laterally shiftable rack having teeth cut at a progressively increasing angle with reference to the teeth of the pinion, and a thermostat operatively connected to the rack and adapted to shift said rack laterally and correct indicator errors due to temperature changes.

3. In a spring scale, the combination of an indicator, and indicator pinion mounted in a relatively fixed position and a laterally shiftable rack having teeth cut at a progressively increasing angle with reference to the teeth of the pinion, and thermostat means for shifting the rack parallel to the axis of the pinion to compensate for the changes in the stiffness of the springs and the changes in the length of the springs due to changes in temperature.

4:. In a spring scale, the combination of anindicator pinion and a rack having teeth cut at a progressively increasing angle with reference to the teeth of the pinion, means at the lower end of the rack for sl'idably mounting the samefor lateral movement, and a thermostat device connected to said means.

5. In a spring scale, the combination of an indicator pinion having a relatively fixed mounting and a rack having a plurality of teeth out at progressively increasing angles with reference to the teeth of the pinion, a runner, a shaft at the end of the rack, means on the runner for engaging the shaft at the end of the rack, and a thermostat device carried by the runner and connected with the said shaft for shifting the same laterally with reference to the teeth of the pinion.

6. In a spring scale, the combination of an indicator pinion and a rack having a pluralit of teeth, the tooth initially engaging with the rack being inclined at an angle to correct the zero reading of the indicator and the succeeding teeth being cut at progressively increasing angles to compensate for chan es in the stiffness of the springs due to chan es in temperature, and a thermostat for shifting the rack laterally with reference to the pinion.

Sigried at New York city in the county of New York and State of New York this 27th day of May, A,D.1929. p I

SYLVESTER G. AVERELL. 

